Nostalgia Fiction Gundam: Beast is a fan work that is now well over a year old. I very highly doubt that there's an official anime in the works based on it, as such a thing would have had a big announcement by now and likely would've happened a while ago given Gundam: Beast's age.

It's doujinshi design, based on non-exist '90 animated series Mobile Animal Gundam Beast. The book are called Nostalgia Fiction Gundam Beast, follow by three more books Gundam Beast Estrus, Gundam Beast Lizard and Gundam Beast Kagerow, though the last one seem to made in style of sidestory.